1. Field of the Invention
This invention relates generally to audio processing and more particularly to a microphone array system capable of tracking an audio signal from a particular source while filtering out signals from other competing or interfering sources.
2. Description of the Related Art
Voice input systems are typically designed as a microphone worn near the mouth of the speaker where the microphone is tethered to a headset. Since this imposes a physical restraint on the user, i.e., having to wear the headset, users will typically use the headset for only a substantial dictation and rely on keyboard typing for relatively brief input and computer commands in order to avoid wearing the headset.
Video game consoles have become a commonplace item in the home. The video game manufacturers are constantly striving to provide a more realistic experience for the user and to expand the limitations of gaming, e.g., on line applications. For example, the ability to communicate with additional players in a room having a number of noises being generated, or even for users to send and receive audio signals when playing on-line games against each other where background noises and noise from the game itself interferes with this communication, has so far prevented the ability for clear and effective player to player communication in real time. These same obstacles have prevented the ability of the player to provide voice commands that are delivered to the video game console. Here again, the background noise, game noise and room reverberations all interfere with the audio signal from the player.
As users are not so inclined to wear a headset, one alternative to the headset is the use of microphone arrays in order to capture the sound. However, shortcomings with the microphone arrays currently on the market today is the inability to track a sound from a moving source and/or the inability to separate the source sound from the reverberation and environmental sounds from the general area being monitored. Additionally, with respect to a video game application, a user will move around relative to the fixed positions of the game console and the display monitor. Where a user is stationary, the microphone array may be able to be “factory set” to focus on audio signals emanating from a particular location or region. For example, inside an automobile, the microphone array may be configured to focus around the driver's seat region for a cellular phone application. However, this type of microphone array is not suitable for a video game application. That is, a microphone array on the monitor or game console would not be able to track a moving user, since the user may be mobile, i.e., not stationary, during a video game. Furthermore, a video game application, a microphone array on the game controller is also moving relative to the user. Consequently, for a portable microphone array, e.g., affixed to the game controller, the source positioning poses a major challenge to higher fidelity sound capturing in selective spatial volumes.
Another issue with the microphone arrays and associated systems is the inability to adapt to high noise environments. For example, where multiple sources are contributing to an audio signal, the current systems available for consumer devices are unable to efficiently filter the signal from a selected source. It should be appreciated that the inability to efficiently filter the signal in a high noise environment only exacerbates the source positioning issues mentioned above. Yet another shortcoming of the microphone array systems is the lack of bandwidth for a processor to handle the input signals from each microphone of the array and track a moving user.
As a result, there is a need to solve the problems of the prior art to provide a microphone array that is capable of capturing an audio signal from a user when the user and/or the device to which the array is affixed are capable of changing position. There is also a need to design the system for robustness in a high noise environment where the system is configured to provide the bandwidth for multiple microphones sending input signals to be processed.